1. Field of the Invention
The present invention relates to a method for cluster based data in wireless sensor networks, and more particularly, to a method for cluster based data in wireless sensor networks that can improve transmission efficiency of data by concentrating data transmission on a predetermined cluster head to aggregate data.
2. Description of the Related Art
A wireless sensor network is a technology that detects a behavior and an environment of a target by utilizing sensors disposed in a predetermined region, converting the detected information into data, and wirelessly transmitting the data to a sink node collecting data. Various sensor nodes are disposed in a dense region in order to improve the accuracy of data in the wireless sensor network, in particular, an efficient target tracking, monitoring, and surveillance application field.
As a result, many sensor nodes participate in target detection and data transmission even in the case of detecting a single target and as a result, a large amount of duplicated data is generated. When all the data are transmitted to the sink node collecting data without special processing, collision and excessive transmission of data occurs in a network.
This causes unnecessary energy consumption of a sensor network, and decrease the accuracy and reliability of data.
In order to solve the problems, research of a network structure and a data aggregating technology for efficient target tracking is being conducted.
In particular, since the data aggregating technology reduces unnecessary transmissions by transmitting various duplicated data to a data aggregating node in the middle of the network and transmits only aggregated data to the sink node, the data aggregating technology can reduce energy consumption and data transmission delay, and increase the accuracy of data.
A representative example of the data aggregating technologies in a hierarchical network structure may include a static clustering based data aggregating technology.
The static clustering based data aggregating technology transmits data to a cluster head on the basis of a static cluster initially generated in the network. Nodes that detect the target transmit all the detected data to their own cluster heads and the cluster heads receiving data aggregate data and transmit only the aggregated data to the data collection node.
Since the static clustering based data aggregating technology aggregates data by using a cluster constructed before detecting the target, a delay time for additionally constructing the cluster is not generated and as a result, data can be transmitted at comparatively high speed. Further, since a sudden change of the cluster does not frequently occur, the network can be stably maintained.
On the contrary, when various clusters detect one target, each node transmits data to each cluster head and as a result, data is not perfectly aggregated.